Mechanism for attaching welts



Get. 9, 1956 F. AYERS 2,765,758

MECHANISM FOR ATTACHING WELTS Filed July 51, 1953 MECHANISM FOR ATTACHING WELTS inter vivos trust of Newton Elkin Application July 31, 1953, Serial No. 371,524

3 Claims. (Cl. 112-60) In the manufacture of shoes of the well known Goodyear welt type, it has been the usual practice to attach the welt by chain stitching to an innersole rib formed partly at least by cutting a channel in the innersole. The attaching of the welt in this manner causes severe stresses to be placed upon the stitch-receiving rib of the innersole, much more severe in fact than any stresses likely to occur in normal wear of the shoe. This requires that the rib be much stronger than would be required for normal use of the shoe and it is thus unduly heavy and cltunsy in the completed shoe, but is necessary because it has to take the pull of the thread in setting the stitches by the chain stitch sewing machine.

In accordance with the present invention the innersole is not channeled and the rib formed for receiving the welt stitching is secured to one face of the innersole, for example, as shown in my Patent No. 2,345,372 granted March 28, 1944, for Shoe and Method of Making the Same, particular attention being called to Figure 7 of that patent. When the innersole is so constructed, the rib is so angularly disposed relative to the innersole that it permits with special parts as will later appear, the use of a lock stitch sewing machine in securing the welt. Such a machine is provided with work supporting and guiding means so arranged that the rib is supported from opposite sides and is not required to take the stresses incident to pulling the stitches tight as is required in the use of the chain stitch machines heretofore used. The rib can therefore be made much lighter and less clumsy than can a rib requiring a channeling operation and the use of the chain stitch welting machine. This also permits the use of a lighter and more flexible innersole since it does not need to be heavy enough to be channeled. This invention therefore has for an object to provide a combined welt guide and presser foot and a cooperating work support for a lock stitch sewing machine, particularly of the type employing a curved needle and awl, and in accordance with which the welt stitching is located close to the root of the rib. This permits trimming of the shoe so close that no filler between the inner and outersoles is necessary. This avoids bunching in the sole which is uncomfortable to the wearer, and absence of filler acts to further increase the flexibility of the shoe sole.

For a more complete understanding of this invention reference may be had to the accompanying drawings in which:

Figure 1 is a lateral cross sectional view through an assembled upper and innersole in preparation for the welt stitching in accordance with this invention.

Figure 2 is a view similar to Figure l but showing the welt attached.

Figure 3 is a view similar to Figures 1 and 2 but showing the shoe trimmed and the outersole applied.

Figure 4 is a top plan view partly broken away and in section showing the welt being stitched in position by the sewing machine.

Patented Oct. 9, 1956 Figure 5 is a detail sectional View on line 55 of Figure 4.

Figures 6 and 7 are detail sectional views on lines 66 and 77, respectively, of Figure 5.

Figure 8 is a fragmentary perspective view of the sewing machine work support.

Figure 9 is a perspective view of the combined Welt guide and presser foot.

Referring first to Figures 1, 2 and 3, the shoe comprises a flat innersole 1 about the margin of which, at least in the forepart, there is secured to one face, as by cement, a strip 2 which may well be of tape folded substantially centrally of its width. This provides a marginal shoulder 3 for the innersole which lies outside of the stitch-receiving rib. This rib at 4 may be formed of the outer marginal portion of a layer 5 cemented or otherwise secured to the lower face of the innersole member 1 and to the lower face of the folded strip 2. The upper 6, which is shown for simplicity as comprising a single layer, though it might comprise an outer and a lining with such interposed parts as may be desired, is then assembled with the innersole, the marginal portion 7 of the upper materials underlying the extension 3 of the innersole and engaging the outer face of the folded strip 2 within the fold and the marginal portion of the member 5.

The shoe thus assembled is then provided with a welt 10, which is stitched in position as shown in Figure 2, as by lock stitches 11 which extend through the inner edge portion of the welt strip 10 and through the layers 7 and 5. The shoe is then trimmed close, as along the line x-y of Figure 2, and an outersole 15 is secured to the welt strip as by the usual outersole stitching 16, or by any other suitable means.

The operation of securing the welt in position is, however, concerned with the present invention.

The curved needle lock stitch machine particularly shown in Figures 4 to 7 includes the curved needle 20 and curved awl 21. As is well known in the art, the awl 21 is caused to pierce the work pieces to be stitched together from beneath, by motion about its center of curvature and then it is given a motion laterally or parallel to its center of oscillation to feed the work piece sufficiently to bring the awl into the plane of the oscillation of the needle 20. The awl is then retracted from the work and the needle passes through the holes made by the awl and places one of the threads of the lock stitch which is engaged by a second thread from a shuttle mechanism, not shown herein but well known in the art.

Due to the relative positions of the stitch receiving rib, the welt, and the under face of the reinforced innersole, the rib and associated parts may be held between a presser foot and a work support during the stitching operation so that these parts take the pull of the threads and thus relieve the rib itself from the strain of such pulling in contrast with the usual chain stitch machine in which the work piece is unsupported on one side of the rib.

Referring to Figures 4 to 7, at 25 is indicated a presser foot, which in this case, is provided with an extension 26 formed with a slot 27 therethrough which acts as a guide for the welt strip 10 which is fed therethrough with its inner edge portion pressed against the outer face of the upper 6 in the angle formed opposite to the innersole extension 3. This presser foot and guide will be described more fully later. The shoe is supported beneath the stitching rib on the supporting block 35. This block 35, as shown best in Figures 5, 6 and 8, is provided with a flat top face 38 and has a forward pointed end 39, the portion 4 of the rib being supported directly on the top face 38. This block is provided with a longitudinal slot 40 which opens through the top face 38 and provides room for the passage of the awl 21 which forms the holes through which the stitches are passed by the needle and also feeds the work through the machine by a lateral motion when the awl is in engagement with the work piece and the presser foot is lifted to bring the hole made by the awl into the needle path.

After this feed motion, which is longitudinal of the slot 40, the presser foot descends to clamp the work against the work support in the manner well known in the art, the awl is retracted, and the needle passes through the holes left by the awl to place the stitches. Not only does this slot 40 open up through the top face 38 of the work support, but it is also open laterally through the outer wall of the block in order that the awl may pass close to the face of the reinforcement 5, the margins of which form the inner face of the stitch-receiving rib. Thus the stitching is placed into the angle at the fold of the reinforcing strip close to where it leaves contact with the innersole member 1 and contacts the upper margin 7 and is placed so close to the root of the rib that the shoe can be trimmed oh closely as shown by the line x--y in Figure 2. The outersole may then be applied in direct face to face contact with the lower face of the innersole without requiring the use of any filler therebetween.

The combined presser foot and welt guide is also specially constructed. As shown in Figures 4, 7 and 9, the welt guide slot 27 is formed angular and shown as rectangular, the angle being adjacent to one edge of the welt at the usual stitch-receiving groove 50 therein to form a short and a long leg. The main portion of the welt is held substantially upright in the long vertical leg of the guide while the inner edge of the welt adjacent to the groove 50 is arranged substantially horizontal within the short leg and butts against the adjacent side face of a forward extension 51 of the presser foot which lies along and substantially opposite to the edge of the slot 40 of the work support 38. This extension 51 lies alongside of the awl during the feed motion of the latter from its retracted position just forwardly of the forward end of the welt guide to its advanced position in alinement with the needle, and while it is raised slightly during this feed so that the work is released for feeding, it supports the work closely adjacent thereto. The inner side of the presser foot extension is in substantial alinement with the end of the short leg of the welt guide. At this time, also, the work is not subjected to stresses laterally of the rib since the awl is not then moving lengthwise and the needle is out of engagement with the work. When the awl pierces the work, and also when the needle passes through the hole formed by the awl and while the stitch is being I tightened in the work, the work is held clamped between the presser foot and the work support. The awl pierces the work close to the forward end of the welt guide portion and adjacent to the extension 51 in the angle therebetween and extends through the welt groove in which the stitch is tightened.

It will be seen from the foregoing description that the work is supported from both faces during the stitching operation so that the stitch-receiving rib of the innersole and the parts secured thereto are free from the pulling stresses such as are exerted thereon during the attachment of a Welt in a chain stitch machine, and that consequently the rib may be formed much lighter, and the innersole, not having to be channeled may also be formed of thinner stock, thus materially lightening the shoe and providing for a more flexible sole.

From the foregoing description it will be evident to those skilled in the art that various changes and modifications may be made therein without departing from the spirit or scope of this invention.

I claim:

1. In combination, a presser foot, 21 welt guide member carried by said presser foot, said felt guide member being provided with a substantially l -shaped slot to receive a welt bent along the stitch-receiving groove, 2. forward extension formed on said presser foot, the inner side face of said extension extending across and in abutting engagement with the outer end of the shorter leg of the L-shaped slot in the welt guide member, the lower face of said forward extension being in alinement with the lower face of the welt guide member.

2. In combination, a presser foot, a welt guide member carried by said presser foot, said welt guide member being provided with a substantially L-shaped slot to receive a welt bent along the stitch-receiving groove, a forward extension formed on said presser foot, the inner side face of said extension extending across and in abutting engagement with the outer end of the shorter leg of the L- shaped slot in the welt guide member, the lower face of said forward extension being in alinement with the lower face of the welt guide member, a support for a lasted shoe having a fiat top face terminating at its edge in alinement with the outer face of the welt guide member and having an awl-receiving slot opposite to the edge of said extension, said slot being open at an intermediate portion of its length on its outer face, and an awl mounted for motion lengthwise of itself to pierce and retract from the shoe and for traversing lengthwise of said slot between the presser foot extension and the inner edge of such slot, said awl being adapted to feed the shoe and welt in superposed relation between the shoe support and the presser foot.

3. In combination, a presser foot, a welt guide member carried by said presser foot, said welt guide member being provided with a substantially L-s'haped slot to receive a welt bent along the stitch-receiving groove, a forward extension formed on said presser foot, the inner side face of said extension extending across and in abutting engagement with the outer end of the shorter leg of the L-shaped slot in the welt guide member, the lower face of said forward extension being in alinement With the lower face of the welt guide member, and a support for a lasted shoe arranged beneath the presser foot and having a flat top face provided with an edge disposed parallel to an edge of the presser foot extension and defining therewith a slot for the passage of sewing instruments therethrough.

References Cited in the file of this patent UNITED STATES PATENTS 510,655 Stinchfield Dec. 12, 1893 1,212,841 Stritter Jan. 16, 1917 2,115,907 Engel May 3, 1938 2,201,060 Terzian May 14, 1940 2,363,976 Kline Nov. 28, 1944 2,669,953 Slinkard Feb. 23, 1954 

